NC0020435_Instream Assessment_19810731

NPDES DOCIMENT !,CANNIN` COVER :MEET
NPDES Permit:
NC0020435
Pinetops WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Owner Name Change
Instream Assessment(67b
Speculative Limits
Environmental Assessment (EA)
Document Date:
July 31, 1981
This document is printed on reuse paper - ignore awry
content or the reireree side

North Carolina Department of Natural
Resources &Community Development
James B. Hunt, Jr., Governor Howard N. Lee, Secretary
DIVISION OF ENVIRONMENTAL MANAGEMENT
July 31, 1981
MEMORANDUM
TO: Ken Schuster, Acting Supervisor
Raleigh Regional Office
• � r• I
FROM: Forrest Westall, Head Orl.," na' by
Technical Services Branc{tOR.EST R. WESTALL
SUBJECT: In -Stream Assessment
Pinetops WWTP
A Level B analysis of Pinetops WWTP's impact on Town Creek has been completed.
According to the most recent data available, the present plant flow is 0.184
MGD, with a BOD5 of 23 mg/1, NH3-N of 10.8 mg/1 and D.O. of 2 mg/1. The
ultimate BOD* used in the modeling analysis was 66.2 mg/1.
Assuming the treatment efficiency of the plant will reamin the same with the
increased loading, the effects of an additional 24,400 gpd are noted in the
attached table. With the additional flow, another 0.1 mile of Town Creek
is expected to have D.O. values less than the 5 mg/1 stream standard. Also,
the D.O. minimum is predicted to drop 0.4 mg/1 from 2.7 mg/1 to 2.3 mg/1 at
the mouth of Town Creek.
According to self -monitoring reports, D.O. violations have occurred downstream
of the plant. However, these reports have indicated D.O. violations upstream
as well. This may imply that drainage from swampy areas has a significant impact
on backgroundwater quality at certain times of the year. Also, the downstream
monitoring station is located just below the discharge. The model predicts the
D.O. sag point to be 6 miles below the outfall just above Town Creek's confluence
with the Tar River. Thus, D.O. violations more severe than those indicated by
self -monitoring data are likely to occur on Town Creek due to the Pinetops
WWTP. No impact is predicted to occur to water quality in the Tar River from
this discharge.
If you have any questions concerning this analysis, please give me a call.
cc: Randy Williams
Arthur Mouberry
*BODu = BOD5 + 4 (NH3-N) = 23 + 4 (10.8) = 66.2 mg/1
P. O. Box 27687 Raleigh, North Carolina 2761 1
An Equal Opportunity Affirmative Action Employer

Summary
The Pinetops WWTP discharges into Town Creek 1.0 mile above the confluence
with Bynums Mill Creek. Both of these are class "C" streams. Town Creek
empties into the Tar River 5 miles below this confluence. The drainage
area and 7Q10 flow at the point of discharge are 162 sq miles and 0.6 cfs,
respectively. Bynums Mill Creek adds 0.1 cfs under low flow conditions.
The velocity of flow in Town Creek was assumed to be 0.5 fps.
The D.O. of Town Creek is predicted to drop to than 5 mg/1 at a distance
of 0.5 miles below the Pinetops discharge under present loading. If
24,400 gpd are added to the treatment plant and the same level of treatment
is achieved, the D.O. standard will be met for only 0.4 miles. In both
cases, the D.O. continues to sag under 7Q10 conditions the entire length
of Town Creek. It reaches a minimum of 2.7 mg/1 under present loading at
the confluence with the Tar River and is predicted to sag to 2.3 mg/1 if the
loading is increased by 24,400 gpd.

Table 1.
# Miles
D.O. less than D.O.min Location of
Flow 5 mg/1 (mg/1) D.O. Minimum
0.184 5.5 2.7 just above confluence
with Tar River on Town
Creek
0.2084 5.6 2.3 just above confluence
with Tar River on Town
Creek

6760
atAxoos azle;6,7not,
/4140% a3pni/i
= 01/1
/1)14 or 10,
QA) = , /S* mq�i
dalet. audtLea.e
/UCPvr�, is re u preoio 05
tiock /
,2 f,Fe/.
500a# =
a 6, g
(0, /)
7gto = o,cv cis
S/o
ElGv = S'O
.0(+ s & sAive);
'9go =0
hleryz,o,
Wei a
6)0 ktrnici
130vw1t = 66.a,//
0, 0 . 7- .2 )7,4
4/iiofr? fl///Cr
L-= 5,0 fry),'.
9Z' . 0& j (o,ifs - e ilvm t ,b

DIVISION OF ENV RONMENTAL MANAGEMENT
June 12, 1981
MEMORANDUM
TO: Ken Schuster, Acting Supervisor, Raleigh Regional Office
OM: Forrest Westall, Head, Technical Services Branch
SUBJECT: In -Stream Assessment
Pinetops Wastewater Treatment Plant
Edgecombe County
A Level B analysis of Pinetops Wastewater Treatment Plant's impact
on Town Creek has been completed. According to self -monitoring data
averaged from January through March 1981, the present plant flow is
0.110.MGD. Effluent BOD5 averages 18 mg/1 while NH3-N is 11.4 mg/1.
This would indicate that the effluent has a BOD ultimate of 63.6 mg/1*.
This value was used as input into the model.
No dissolved oxygen data was available for the effluent. In order to
estimate the impact from the addition of 13,000 gpd, the model was run
with effluent D.O. values of 0, 3 and 5 mg/1. The accompanying table
compares the predicted effect upon water quality of the effluent
at present flow conditions (Qw am .110 MGD), as well ad the 13,000 gpd
addition (Qw 0.123 MGD). Please note that both the BOD5 and NH3-N
loading were assumed to remain constant with increased expansion.
According to self -monitoring reports, D.O. violations have occurred
downstream of the plant. However, self -monitoring reports have
indicated D.O. violations upstream as well. This may +n;.1y that
drainage from swampy areas has a significant impact on background
water quality at certain times of the year. Also, the downstream
monitoring station is located just below the discharge. The model
predicts the D.O. sag to occur just above the point where Town Creek
enters the Tar River which is six miles below the outfall. Thus, D.O.
violations more severe than those indicated by self -monitoring data
are likely to occur on Town Creek due to the Pinetops WWTP.
* BODu BOD5 + 4(NH3-N) am 18 + 4(11.4) is 63.6 mg/1
FW:cs
Attachments
cc: P.andy'Williams & Arthur Mouberry

Reach 1:
Town Creek
D.O. min.
Location of min. (mi. below
discharge)
Flow a 0.110 MGD Flow at 0.123 MGD
DO a 5
DOa3
DO
DO az 5
D00.3
DOa 0
5.9
1.0
5.5
1.0
5.0
1.0
5.8
1.0
5.4
1.0
4.8
1.0
D.O. @eend (L.P. 1)
# of miles of D.O.
violation
5.9
0
5.5
0
5.0
0
5.8
0
5.4
0
4.8
0.2
Reach 2:
Town Creek
below confluence with
Bynums Mill Creek
Mile points below Bynums
Mill Cr. where D.O. goes
below 5 mg/1
D.O. value @ sag point
(mouth of Town Cr. -
confluence with Tar River)
2.2-5.0
4.5
1.6-5.0
4.4
0.6-5.0
4.2
1.8-5.0
4.3
1.2-5.0
4.1
0.5.0
3.9

SUMMARY OF PINETOP'S WWTP IMPACT
The Pinetop WWTP discharges into Town Creek 1.0 miles above the
confluence with Bynums Mill Creek. Both of these creeks are class
"C" streams. After merging with Bynums Mill Creek, Town Creek then
flows, another 5 miles before emptying into the Tar River. The
drainage area and 7Q10 flow at the point of discharge are 162 mi2
and 0.6 cfs respectively (USGS estimates). Bynums Mill Creek adds
another 0.1 cfs to Town Creek under 7Q10 conditions. The model vas
run at a design temperature of 26°C. A velocity of 0.5 fps was used
for Town Creek.
After the discharge mixes with the waters of Town Creek, the D.O. of
•the stream starts decreasing due to breakdown of BOD. However, except
for a plant flow of 0.123 MOD and an effluent D.O. of 0, no dissolved
oxygen violations are predicted to occur above Bynums Mill Creek.
After Bynum gills Creek enters Town Creek, the D.O. of Town Creek
continues to decrease as deoxygenation exceeds reaeration. The
D.O.m .nimum is reached just before Town Creek enters the Tar River.
The predicted D.O. minimum ranges from 3.9 to 4.5 mg/1 under the
various flow and effluent D.O. conditions with which the model was
run.

DIVISION OF ENVIRONMENTAL MANAGEMENT
June 3, 1981
MEMORANDUM
TO: Forrest Westall
Supervisor, Technical Services
FROM: Lars D. Godwin
Permits Supervisor
Raleigh Regional Office
SUBJECT: Town of Pinetops
NPDES Permit No. NC0020435
Special Order By Consent
Edgecombe County
The Town of Pinetops has requested a Special Order By Consent to allow
additional sewer extensions. The existing facility is a 0.26 MGD trickling filter
plant which discharges into Town Creek a Class "C" stream in the Tar River Basin.
The following list represents the latest self monitoring monthly average (Jan. -
March, 1981) and the monthly averages for 1980:
Parameter
Flow
BOD5
TSS
Fecal Coliform
NH3-N
D.O.
pH
Jan. - March, 1981
0.110 MGD
18 mg/1
12 mg/1
Not Available
11.4 mg/1
Not Available
7.2 s.u.
1980
0.149 MGD
22 mg/1
19 mg/1
15/100 ml
8 mg/1
1.2 mg/1
7.1 s.u.
o. T( '-
yy.QCtsLusysm.( ta
o
It is recommended that you use the monitoring data from 1981 where
available. The additional waste flow from the proposed low income homes and
Wilshire Apartments is 13,000 gpd.
The above data should be used to evaluate potential stream degradation,
i.e., impact on water quality of the proposed additional wastewater. Your analysis
will be used to evaluate the proposed SOC under the provisions of G.S. 143-215.
67(b). A wasteload request was completed April 8, 1981.
LDG/tbj

l t�l L0V✓.2Sf�, P��I
hAdo-nti 4-611 rt3 aflekk
e cie - Odeon 6♦ CoteK-T
T cox, o' Fiene4°rS
(41)r / 1 use- 'cal( o.a.- ' o w VYtOcefe_ i rece d (. do e_
Co v iti e n v et „deo S,
1Tht \rec_ese (4) _ twx_otko+ri
a
D
i
‘e-
u_5e
W= a. iro MGq
43s--t= 806Lt= at
(-(3--fu-=.- i-L
b i.s ha-F 0..0a ue. _ -r,ro, ..se /r .mac
refor-F) w ;((
ere- (S 00A a. r l C i P �'�a "l _l G - a R.
o® tota ft &LD
dee(t7Ltee
i -1---ce( Pow lio 0 to= (9,/a3/14
--11
ketsi-s e_e sn -* Gas - ` -A L,.
o c..L3 = O. 0-1-)".. I/ 3 (A);
sq. le `e- 44-C-1".
'• dicyle,.
T 42- IC es (A... O.,
ti /
Va

/ e 0 e- ( ( s .1e- //o 0 -----:-..72;e4- ritr
V) 01( V
41 (I 7. v.
—Prow. y viGtms
piJe 3 0 t,KA.P (c-Is
vko(; cet4ek 1/1 iff () r cAive_c,k sf"